1. Field
The present disclosure relates to a 3-dimensional displaying apparatus, and more particularly to a 3-dimensional displaying apparatus and a driving method thereof, in which a set of line sources are driven alternately to minimize the change of brightness of image information and crosstalk between adjacent visual fields and to prevent pseudo-stereoscopic vision in a case where a horizontal location of an observer is changed.
2. Description of the Related Art
In recent, to meet the increasing demands on displaying apparatuses capable of realizing 3-dimensional images, which can give substantial stereoscopic views, not available in existing 2-dimensional images, various kinds of displaying apparatuses have been developed.
When seeing an article existing in the nature, a person feels cubic effect since visual angles of both eyes are slightly different from each other when the person looks at the article. Image information of the article with slightly different visual angles are formed on the retinas through right and left eyes, and the person feels cubic effect while the formed image information of both eyes is transferred to the brain through optic nerves.
In detail, a 3-dimensional image is generally realized by means of stereoscopic principles through both eyes. Thus, a displaying apparatus capable of displaying stereoscopic images by using the binocular disparity caused by the fact that both eyes are spaced apart from each other by about 65 mm is proposed. To explain the realization of 3-dimensional images in more detail, right and left eyes looking at the displaying apparatus respectively observe different 2-dimensional images. If both images are transferred to the brain through the respective retinas, the brain accurately fuses the images to generate an original 3-dimensional image with presence and immersion, which is generally called stereography.
A non-glasses 3-dimensional image displaying apparatus has a parallax separation unit in front of an existing 2-dimensional image displaying apparatus to transfer images of different visions to right and left eyes of an observer so that the observer may feel cubic effect. The parallax separation unit for giving cubic effect may be a parallax barrier plate or a lenticular lens sheet. FIG. 1 shows an example of realizing a 3-dimensional image by using the parallax barrier plate as a parallax separation unit.
FIG. 1 illustrates the principle of a 2-visual field 3-dimensional displaying apparatus as an example. Referring to FIG. 1, the 2-visual field 3-dimensional displaying apparatus 100 includes a general 2-dimensional image displaying panel 110 and a parallax barrier plate 130 disposed spaced apart at the front of the image displaying panel 110. Pixels formed at the image displaying panel 110 include left eye image pixels 13 and right eye image pixels 15. The parallax barrier plate 130 has an open portion and a barrier portion. Image information emitted from the left eye image pixels 13 and the right eye image pixels 15 passes the open portion but does not pass the barrier portion. The image information passing through the open portion is focused at a designed observing distance. Meanwhile, among locations of an observer at the designed observing distance, A location allows measuring only the image information of the left eye, and B location allows measuring only the image information of the right eye.
However, the method for displaying 3-dimensional images by means of parallax separation by the parallax barrier plate 130 has several problems to be solved. First, in a case where the eyes are horizontally moved so that the left eye is positioned at a D location and the right eye is positioned at an E location as an example, image information emitted from the left eye image pixel 13 and the right eye image pixel 15 are applied to the left and right eyes at the same time, as shown by dotted lines in FIG. 1. As a result, a clear 3-dimensional image cannot be observed. This phenomenon is called as crosstalk occurs between visual fields.
Second, in a case where the observer moves in a horizontal direction so that the left eye of the observer is positioned at a B location and the right eye is positioned at a C location, the left eye sees the image information emitted from the right eye image pixel 15 and the right eye sees the image information emitted from the left eye image pixel 13. As a result, pseudo-stereoscopic vision is generated so that the observer cannot see normal 3-dimensional stereoscopic information.
Third, the brightness of image is not uniform in the corresponding visual field, and the brightness of image varies as the eye moves in a horizontal direction. This problem will be described in detail with reference to FIG. 2.
FIG. 2 is an optic distribution graph of 3-dimensional image at each visual field by a general parallax separation unit. Here, the horizontal axis represents a horizontal location at an observing distance, and the vertical axis represents the intensity of light. Referring to FIG. 2, in a case where the left and right eyes are respectively positioned at a first visual field (depicted by a solid line) and a second visual field (depicted by a dotted line) and then move right or left in a horizontal direction as an example, it could be found that the brightness of the corresponding image is decreased and also crosstalk occurs since image information in an adjacent visual field is mixed.
The above description is based on the case where the parallax barrier plate is used as a parallax separation unit, but the same problem occurs even when a lenticular lens sheet is used.